Unsaturated alkenes are useful as monomers and comonomers for the formation of commercially valuable polymers. The conversion of lower value saturated hydrocarbons into higher value unsaturated hydrocarbons is economically desirable. Oxidative dehydrogenation of saturated hydrocarbons to form unsaturated hydrocarbons has been accomplished using catalysts in high temperature gas phase reactions.
Numerous catalysts which can be used for the oxidative dehydrogenation of saturated or paraffinic hydrocarbons have been reported. Mixed nickel and tin oxides have been disclosed in U.S. Pat. No. 3,745,194; U.S. Pat. No. 3,801,671; and U.S. Pat. No. 5,086,032. Complex metal oxide catalyst including vanadium and aluminum for oxidative dehydrogenation of hydrocarbons has been disclosed in U.S. Pat. No. 4,046,833.
Catalysts, having crystalline structures, useful for the oxidative dehydrogenation of saturated hydrocarbons to form unsaturated hydrocarbons are known. U.S. Pat. No. 5,772,898 discloses a metallo manganese oxide having a hollandite structure and an intracrystalline pore system.
U. S. Pat. No. 4,777,319 discloses a catalyst for oxidative dehydrogenation of hydrocarbons using metal vanadate compounds which are described as having crystalline structures. U.S. Pat. No. 5,139,988 discloses an iron-antimony containing oxide catalyst in which the iron antimonate is crystalline. U.S. Pat. No. 4,973,793 discloses crystalline catalyst compositions having iron, oxygen and at least one other metallic element. U.S. Pat. No. 4,658,074 also discloses crystalline catalysts having iron, oxygen and at least on other metallic element.
Calcination is commonly used as one step in the process of preparing catalysts useful for oxidative dehydrogenation. U.S. Pat. No. 3,860,534 disclosed high temperature calcinations at 700.degree. C. to 900.degree. C.
A desire still exists in the art to develop catalyst that will promote a high conversion of alkane starting material with high selectivity to an alkene product material of the same carbon number so as to enable the attainment of a high yield of product per pass.